gh-158688: Fix crash when dumping a deep chain of awaiting tasks

[deadlovelll]

Fix crash when dumping a deep chain of awaiting tasks

For more details see gh-158688

[maurycy]

I think this is a duplicate of #153365

[deadlovelll]

I think this is a duplicate of #153365

hi! yes, i see problems overlaps. But solutions differ

#153365 keeps no visited set, so the check if there are infinite loop or not only depends on the const (MAX_TASK_WAITER_WALK_TASKS). For example repro from #158688 with range(20000) instead of 5000 will raise an RuntimeError

RuntimeError: Too many task waiters (possible infinite loop)

But actually the program does not produce the infinite loop

I don't think these PRs compete, #153365 covers things mine doesn't. Feel free to cherry pick this commit into your PR =)